The format for conference proceedings published as an edited book chapter is the same as for a chapter in an edited book. For a conference paper in a journal please find under journal article.
If there are three or more authors of a work only the first author should be cited followed by et al. and the date
According to Bendnel et al. (2019)....
...(Bendnel et al., 2019).
Last name, Initial(s)., & Last name, Initial(s). (Year). Chapter title. In Initial(s). Last name & Initial(s) Last name (Eds.), Book title (pages of chapter). Publisher. DOI
Bedenel, A.-L., Jourdan, L., & Biernacki, C. (2019). Probability estimation by an genetic algorithm in web insurance. In R. Battiti, M. Brunato, I. Kotsireas, & P. Pardalos (Eds.), Lecture notes in computer science: Vol.11353. Learning and intelligent optimization (pp. 225–240). Springer. https://doi.org/10.1007/978-3-030-05348-2_21